Abstract:

A housing for a combustion chamber assembly is provided. The housing
includes a wall device made of metal material, and an insert device made
of ceramic material. The insert device is attached to the wall device
such that the insert device forms a part of an inner wall of the housing
and the wall device forms an outer wall of the housing.

Claims:

1.-10. (canceled)

11. A housing for a combustion chamber assembly, comprising:a wall device
made of metal material; andan insert device made of ceramic
material,wherein the insert device is attached to the wall device such
that the insert device forms a part of an inner wall of the housing and
the wall device forms an outer wall of the housing.

12. The housing according to claim 11, wherein the insert device and the
wall device are brazed together.

13. The housing according to claim 11,wherein the wall device comprises
force transmitting elements, andwherein the force transmitting elements
are adapted for transmitting bearing force of the wall device.

14. The housing according to claim 12,wherein the wall device comprises
force transmitting elements, andwherein the force transmitting elements
are adapted for transmitting bearing force of the wall device.

15. The housing according to claim 11, wherein the wall device comprises a
cooling opening.

16. The housing according to claim 14, wherein the wall device comprises a
cooling opening.

17. The housing according to claim 11,wherein the insert device is
attached to the wall device in a detachable manner.

18. The housing according to claim 17,wherein the insert device comprises
engagement elements, andwherein the engagement elements are adapted for
being mechanically coupled with an exchanging tool.

19. The housing according to claim 11, wherein the insert device comprises
a plurality of insert elements.

20. The housing according to claim 18, wherein the insert device comprises
a plurality of insert elements.

21. A combustion pre-chamber, comprising:a housing witha wall device made
of metal material, andan insert device made of ceramic material, the
insert device being attached to the wall device,wherein the wall device
font's an outer wall of the combustion pre-chamber, the profile of the
outer wall being cylindrically, andwherein the insert device forms a part
of the inner wall of the combustion pre-chamber, the profile of the inner
wall being cylindrically.

22. The combustion pre-chamber according to claim 21, wherein the insert
device and the wall device are brazed together.

23. The combustion pre-chamber according to claim 21,wherein the wall
device comprises force transmitting elements, andwherein the force
transmitting elements are adapted for transmitting bearing force of the
wall device.

24. The combustion pre-chamber according to claim 21, wherein the wall
device comprises a cooling opening.

25. The combustion pre-chamber according to claim 21,wherein the insert
device comprises engagement elements, andwherein the engagement elements
are adapted for being mechanically coupled with an exchanging tool.

26. A pilot burner device, comprising:a housing witha wall device made of
metal material, andan insert device made of ceramic material, the insert
device being attached to the wall device,wherein the wall device forms an
outer wall of the pilot burner device,wherein the insert device forms a
part of the inner wall of the pilot burner device, andwherein the part of
the inner wall of the pilot burner device comprises a pilot burner face.

27. The pilot burner device according to claim 26, wherein the insert
device and the wall device are brazed together.

30. The pilot burner device according to claim 26,wherein the insert
device comprises engagement elements, andwherein the engagement elements
are adapted for being mechanically coupled with an exchanging tool.

[0002]The present invention relates to a housing for a combustion chamber
assembly and a method of producing a housing for a combustion chamber
assembly.

ART BACKGROUND

[0003]In combustion chamber assemblies the combustion chamber and the
combustion pre-chamber are exposed to heat during engine operation.
Conventional combustion chamber assembly components are made of metal
material, so that the heat during turbine operation leads to abrasion of
the metal material. Moreover, streaming of a fluid inside of a combustion
chamber assembly may be turbulent, so that a high heat will be exposed to
the metal components.

[0004]In conventional designs of combustion chamber assemblies a
compressor may be used to discharge air and thus to wash the outer skin
of the combustion chamber assembly in order to reduce the metal
temperature within acceptable limits for the component life.

[0005]JP 10 10 36 74 A discloses a combustion for a gas turbine wherein a
dome part is formed of metal and a separate cylindrical part on the
downstream side of the dome is formed of ceramic.

[0006]US 2006/0010879 A1 discloses a mounting of a turbine nozzle on a
combustion chamber having CMC walls (CMC: ceramic matrix composite) in a
gas turbine. A turbine nozzle connected to a combustion chamber may be
formed of ceramic material.

[0007]WO 2007/066052 discloses a joint between a metal part and a ceramic
part based on SiC and/or C (SiC: chemical formula for "silicon carbide";
C: chemical element "carbon"). A metal part and a ceramic part may be
joined together wherein a first spacer and a second spacer separates the
metal part and the ceramic part.

SUMMARY OF THE INVENTION

[0008]It may be an object of the present invention to provide a proper
housing for a combustion chamber assembly for a turbine.

[0009]In order to achieve the object defined above, a housing for a
combustion chamber assembly and a method of producing the housing
according to the independent claims are provided.

[0010]According to a first exemplary embodiment of the present invention,
a housing for a combustion chamber assembly is provided. The housing
comprises a wall device made of metal material and an insert device made
of ceramic material. The insert device is attached to the wall device in
such a way that the insert device forms a part of an inner wall of the
housing and the wall device forms an outer wall of the housing.

[0011]According to a further exemplary embodiment, a method of producing
the above-described housing is provided. The method comprises the step of
attaching the insert device to the wall device in such a way that the
insert device forms a part of an inner wall of the housing and the wall
device forms an outer part of the housing.

[0012]The combustion chamber assembly may comprise for instance a pilot
burner body, a combustion pre-chamber, a mixing tube and/or a combustion
chamber. Each of the elements of the combustion chamber assembly may
comprise a separate housing according to the above mentioned exemplary
embodiment, i.e. a housing comprising the wall device made of metal and
the insert made of ceramic material. Besides that, the combustion chamber
assembly may comprise one common above mentioned housing as denoted
above.

[0013]The wall device may form the outer wall of the housing, wherein to
the inner surface of in the interior side of the housing the insert
device may be attached. Because the insert device may be made of ceramic
material, an improved heat resistance in comparison to the metal material
is achieved.

[0016]By the present invention, an inner side of the housing may be made
of an insert device made of ceramic material, so that a proper heat
resistance may be provided in comparison to metal material. Compressor
discharged air for cooling the metal material may be not longer necessary
because the metal material of the outer wall device is not longer exposed
directly to the heat inside of the combustion chamber assembly. Thus,
without the compressor discharged air, the outer skin respectively the
wall device made of metal material may be kept within acceptable
temperature limits, so that the component life may be improved. Further
expensive cooling devices, such as air compressors, may be not longer
necessary.

[0017]The insert device may be attached to the inside of the wall device
in such a way, that the housing provides a hybrid design. With other
words, the insert device may be attached directly with e.g. fully
contact, to the inside of the wall device.

[0018]Due to the ceramic insert, the housing may be temperature resistant
without applying temperature protecting coatings (e.g. MCrAlly coatings)
to the inner wall of the housing. In conventional housing the temperature
protecting coatings may go off easily from the inner wall, so the inner
wall have to be coated again after short operating periods. This may lead
to shorter maintenance periods, so that maintenance costs may be reduced.

[0019]According to a further exemplary embodiment of the present
invention, the insert device and the wall device are brazed together. By
brazing the insert device to the wall device, a rigid and fixed
connection may be provided. By brazing the insert device and the wall
device together, between the insert device and the wall device no air
leakage may occur, so that a reduction in the occurrence of hot gas
leakage to atmosphere may be provided and the safety may be improved.

[0020]According to a further exemplary embodiment of the present
invention, the wall device comprises force transmitting elements, wherein
the force transmitting elements are adapted for transmitting bearing
force of the wall device to adjacent components. I.e. the bearing force
or the supporting force is supported only by the wall device, so that a
reduced tension and stress caused by bearing forces will transferred to
the insert device. Thus, the defect of the ceramic material of the insert
device may be reduced because the ceramic material is in general not
capable to be exposed to bending moments or tension forces. On the other
side, the metal material of the wall device is qualified for transmitting
such forces. Thus, the qualification of each material, namely of the
metal material and the ceramic material, are applied due to its
qualifications and characteristics, so that the lifetime of the housing
may be improved. I.e. the insert device is applied for preventing an
overheat of the wall device made of metal material, and the wall device
is applied for transmitting the mechanical load for reducing stress and
tensions in the insert element.

[0021]The transmission of the mechanical load respectively the bearing
force may be provided by the force transmitting elements. The force
transmitting elements are attached to the wall device or are formed with
the wall device. The force transmitting elements may be for instance a
flange, a screw hole or other elements adapted for connecting the housing
to another adjacent part or carriers.

[0022]Summarizing, by the exemplary embodiment, the larger part of force
flow that is caused by the supporting of the housing is guided over the
wall device and no part or a reduced part of the force flow is
transferred to the insert device. Thus, an improved utilization of the
best characteristics of each material, respectively metal material and
the ceramic material, may be provided by the (hybrid) housing.

[0023]According to a further exemplary embodiment of the present
invention, the wall device comprises a cooling opening. When providing
cooling openings in the wall element, a cooling fluid, such as air or
other hydraulic fluids, may be used for direct cooling of the ceramic
insert. Thus, the ceramic material of the insert device may stand higher
temperatures of the inner fluid and additionally the wear of the ceramic
material may be reduced. The cooling openings may be provided by a hole
or grooves in the wall device, for example.

[0024]According to a further exemplary embodiment, the insert device is
attached to the wall device in a detachable manner. Thus, when the
ceramic insert is damaged for instance due to wear or due to high
temperature, the insert device may be detached, machined out and
exchanged by a further insert device. Thus, it is not necessary to
exchange the wall device respectively the whole housing when a damage of
the insert device is occurred. Thereby, maintenance costs may be reduced.
Moreover, the insert device may be machined out and re-applied, without
the need of scraping off the housing.

[0025]According to a further exemplary embodiment of the present
invention, the insert device comprises engagement elements, wherein the
engagement elements are adapted for being mechanically coupled with an
exchanging tool. The engagement elements may comprise grooves or other
suitable elements that are adapted for being engaged by an exchanging
tool. With other words, the engagement elements are adapted for being
coupled to an engaging tool, so that the insert device may be machined
out or exchanged from the wall device. The coupling may be provided also
for instance by magnetic engagement elements, so that beneath a
mechanical coupling also a magnetic coupling with the exchanging tool may
be provided.

[0026]According to a further exemplary embodiment of the present
invention, the insert device comprises a plurality of insert elements. By
providing a plurality of insert elements, the thermal growth of the wall
element may be compensated by the plurality of insert elements. I.e. in
general the metal material provides a higher thermal expansion
coefficient in comparison to the ceramic material of the insert device.
Thus, when the insert device is rigidly fixed to the wall device,
tensions and stress arise between the wall device and the insert device
due to the different thermal expansion coefficients. When the insert
device comprises a plurality of (separated) insert elements, the insert
device is flexible, so that the insert elements move for example away
from each other when the metal material of the wall device expands. In
other words, by splitting up the insert device in separate insert
elements, thermal growth mismatches are allowable. Moreover, the crack
growth of the insert elements is advantageously restricted to one insert
element. Thus, when a crack growth occurs in one insert element, the
other insert element remains stable and undamaged. Thus, the lifetime of
the overall insert device may be improved. Moreover, when a defect of an
insert element occurs, only the damaged insert element may be replaced,
so that the maintenance costs may be reduced.

[0027]According to a further exemplary embodiment, a combustion
pre-chamber comprising the above described housing is described. The wall
device forms an outer wall of the combustion pre-chamber, wherein the
profile of the outer wall is cylindrically. The insert device faints a
part of the inner wall of the combustion pre-chamber, wherein the profile
of the inner wall is cylindrically. With other words, the housing of the
present exemplary embodiment is a combustion pre-chamber that is located
in the combustion chamber assembly between e.g. a swirler and a dome
part. The dome part and the swirler may be made of metal material.
Besides the cylindrical shape of the combustion pre-chamber, a cubic or
rectangular shape may also be appreciable.

[0028]According to a further exemplary embodiment of the present
invention, a pilot burner device comprising the above described housing
is described. The wall device forms the outer wall of the pilot burner
device. The insert device forms the part of the inner wall of the pilot
burner device. The part of the inner wall of the pilot burner device
comprises a pilot burner face. The pilot burner is adapted for igniting
the flame into the combustion chamber assembly. The pilot burner body is
e.g. attached to the tubular combustion chamber. Thus, the pilot burner
forms a part of the housing of the combustion chamber assembly. The wall
device respectively the pilot burner outer wall is made of metal material
in order to provide proper supporting characteristics and to keep the
costs of the part down. At the ignition area of the pilot burner device,
the pilot burner face is located. The area of the pilot burner face may
consist of the inner wall of the pilot burner device including the insert
device made of ceramic material. Thus, in the hottest area of the pilot
burner device, a ceramic material may be attached to, so that the
lifetime of the pilot burner device may be improved.

[0029]In conventional pilot burners, the pilot burner bodies are made of
metal which is a compromise material to keep the costs of the part down
and to provide some resistance to the temperature. The pilot burner face
provides for instance a MCrAlly coating to keep the metal temperature
within acceptable limits for component life.

[0030]By the present invention, by adding a ceramic insert device into the
wall device made of metal, the ceramic insert device protects the outer
metal wall device from excessive temperature. Both, the insert device and
the wall device may be connected by brazing. The insert device and the
wall device may form thereby a hybrid housing. In particular, the insert
device may be attached directly without any further intermediate layers
to the wall device. The manufactured (hybrid) housing, respectively the
combination of the insert device attached to the wall device, faun e.g. a
combustion pre-chamber of the combustion chamber assembly. Such a
combustion pre-chamber may be located between a swirler device and a dome
of the combustion chamber assembly. The housing may be attached to other
parts of the combustion chamber assembly, such as the swirler device or
the dome, e.g. by joint connection or flange connections. A brazing of
the housing respectively of the wall device to other parts of the
combustion chamber assembly for supporting the housing may not be
necessary. I.e. the larger part of the bearing load is transferred
through the wall device, respectively the outer metal sleeve. Thus, only
a small part of the load is transferred through the ceramic insert
device, so that the risk of damage, e.g. of crack growth, may be reduced.
Moreover, cooling openings in the metal wall device provides a better
heat transfer directly from the ceramic insert device to the environment
respectively to the air cavity.

[0031]Thus, the embodiments of the present invention provides a more
robust housing for a combustion chamber assembly that is in particular
more robust to excessive temperatures especially during liquid operation,
i.e. when liquid fuel spray hitting the inner wall respectively to the
insert device of the housing. In comparison to the use of metal material,
the hot liquid fuel spray hitting a metallic wall would lead to metal
loss and distortion.

[0032]It has to be noted that embodiments of the invention have been
described with reference to different subject matters. In particular,
some embodiments have been described with reference to apparatus type
claims whereas other embodiments have been described with reference to
method type claims. However, a person skilled in the art will gather from
the above and the following description that, unless other notified, in
addition to any combination of features belonging to one type of subject
matter also any combination between features relating to different
subject matters, in particular between features of the apparatus type
claims and features of the method type claims is considered as to be
disclosed with this application.

BRIEF DESCRIPTION OF THE DRAWINGS

[0033]The aspects defined above and further aspects of the present
invention are apparent from the examples of embodiment to be described
hereinafter and are explained with reference to the examples of
embodiment. The invention will be described in more detail hereinafter
with reference to examples of embodiment but to which the invention is
not limited.

[0034]FIG. 1 shows a schematical view of a housing for a combustion
chamber assembly according to an exemplary embodiment of the invention;

[0035]FIG. 2 illustrates a schematical view of a housing comprising insert
elements according to an exemplary embodiment of the invention;

[0036]FIG. 3 illustrates a schematical view of the housing comprising
cooling openings and force transmitting elements according to an
exemplary embodiment of the invention;

[0037]FIG. 4 illustrates a combustion chamber assembly comprising a
combustion chamber and a combustion pre-chamber according to an exemplary
embodiment of the present invention;

[0038]FIG. 5 illustrates a schematical view of a pilot burner device; and

[0039]FIG. 6 illustrates an overview of a combustion chamber assembly
comprising several housing elements according to an exemplary embodiment
of the invention.

DETAILED DESCRIPTION

[0040]The illustrations in the drawings are schematically. It is noted
that in different figures, similar or identical elements are provided
with the same reference signs.

[0041]FIG. 1 shows a housing 100 for a combustion chamber assembly 600
(see FIG. 6). The housing comprises a wall device 101 made of metal
material and an insert device 102 made of ceramic material. The insert
device 102 is attached to the wall device 101 in such a way, that the
insert device 102 forms a part of an inner wall of the housing 100 and
the wall device 101 fauns an outer wall of the housing 100.

[0042]"Inner" and "outer" is defining the direction to which a wall is
directed. "Inner" wall is directed to the centre of a combustion chamber.
Hot fluid will pass directly at the surface of the inner wall. "Outer"
wall defines a wall directed away from the centre of the combustion
chamber.

[0043]Thus, the hot fluid flow inside of the tube is only exposed to the
insert device 102 made of ceramic material. The wall device 101 made of
metal material is for instance not completely exposed to the hot fluid
flow inside the housing. Thus, the resistance to temperature of the
ceramic material of the insert device 102 is better in comparison to the
metal wall device 101, so that the lifetime of the housing 100 may be
improved.

[0044]FIG. 2 shows a sectional view of the housing 100, wherein the wall
device 101 comprises a plurality of wall elements 201 and the insert
device 102 provides a plurality of insert elements 202. The insert
elements 202 may be attached separately from each other and form together
the insert device 102. Thus, when a crack growth in one insert element
202 occurs, the crack growth will stop at the gap between the insert
elements 202. Thus, when crack growth occur, only a part of the insert
device 102, respectively only the effected insert element 202, will be
damaged. Moreover, only a partial exchange of the insert elements 202 may
be necessary for maintenance purposes. Moreover, to improve the
maintenance and the lifetime of the housing 100, the insert device 102 as
well as the insert elements 202 may be attached to the wall device 101 in
a detachable manner.

[0045]The insert device 102 respectively the insert element 202 may be
attached to the wall device 101 for instance by brazing gluing or by a
press-fitting.

[0046]As an example, two insert elements 202 may form a complete insert
device 102, in which each insert element 202 may be roughly a half tube.
In FIG. 2 the second insert element 202 is not shown. Furthermore,
several insert elements 202 can be present, all of the being a fraction
of a tube and together forming a complete insert device 102.

[0048]When providing cooling openings 301 in the wall device 101 the heat
exchange of the ceramic insert device 102 with the environment may be
improved. Through the cooling openings 301 an outside surface of the
insert device 102 may be cooled. Thus, the temperature within the housing
may be kept in acceptable limits without providing complex cooling
devices that would lead to a higher energy consumption and thus to higher
operating costs.

[0049]Moreover, the force transmitting elements 302 are shown in FIG. 3,
wherein by the force transmitting elements 302 the housing 100 may be
supported or may be attached to other parts of the combustion chamber
assembly 600. Thus, the major part of the load (supporting load) of the
housing 100 is transferred through the wall device 101 and no part or
only a minor part of the load is transferred through the insert device
102. Thus, stress caused by load may be reduced at the insert device 102
or at the insert element 202. The force transmitting elements 302 may
comprise a flange, a thread, a sleeve or a connection edge. Also other
force transmitting elements 302 may be applicable that are adapted for
transferring a (supporting) load force from the housing 100 or the wall
device 101 to other (adjacent) parts of the combustion chamber assembly
600.

[0050]Moreover, FIG. 3 shows engaging elements 303 of the insert device
102. The engagement elements 303 may comprise grooves in the insert
device 102 for providing a coupling with an exchanging tool for a better
machining out and decoupling of the insert device 102 with the wall
device 101. Moreover, the engagement elements 303 may comprise magnetic
elements for providing a magnetic coupling to the exchanging tool.

[0051]FIG. 4 illustrates a combustion chamber 401 and a combustion
pre-chamber 402 of a combustion chamber assembly 600 (see FIG. 6). The
combustion chamber 401 may comprise a housing 100 and the combustion
pre-chamber 402 may comprise a further housing 100. Both housings 100 of
the combustion chamber 401 and the combustion pre-chamber 402 may be
separate housings 100 combined detachably with each other or both, the
combustion chamber 401 and the combustion pre-chamber 402 comprise one
common housing. A part of the insert device 102--located in the area of
the pre-chamber 402--or a part of a further insert device 403--located in
the area of the combustion chamber 401--may overlap with the wall device
101. With the force transmitting elements 302, as shown in FIG. 4 by a
flange, a connection to adjacent parts of the combustion chamber assembly
600 may be provided, wherein the load respectively the supporting load
may be guided through the wall device 101 and not through the insert
device 102.

[0052]FIG. 5 illustrates via a sectional view a pilot burner device 501
and a pilot burner face 502 which both are basically, with possibly some
exceptions, rotational symmetric. The pilot burner device 501 forms the
wall device 101. The pilot burner device 501 may comprise the force
transmitting elements 302 for attaching the pilot burner device 501 to
other parts of the combustion chamber assembly 600. To the inner wall of
the pilot burner device 501 the pilot burner face 502 is located facing
in the direction of the combustion chamber. At the pilot burner face 502
a flame of the combustion chamber assembly 600 may be ignited, so that at
the location of the pilot burner face 502 high temperature may occur.
Thus, when providing the pilot burner face 502 as the insert device 102,
the insert device 102 may stand higher temperatures because the insert
device 101 is made of ceramic material.

[0053]FIG. 6 illustrates an overview of a combustion chamber assembly 600.
The combustion chamber 401 and the combustion pre-chamber 402 are formed
tubular respectively cylindrical. To one side respectively to the
combustion pre-chamber 402, the pilot burner device 501 is attached to.
The pilot burner device 501 closes the tubular combustion chamber 401
respectively combustion pre-chamber 402 at the upstream side (stream
direction indicated by the arrows). Between the pilot burner device 501
and the combustion pre-chamber 402 a swirler device 601 may additionally
attached.

[0054]It should be noted that the term "comprising" does not exclude other
elements or steps and "a" or "an" does not exclude a plurality. Also
elements described in association with different embodiments may be
combined. It should also be noted that reference signs in the claims
should not be construed as limiting the scope of the claims.